Means for adjusting the touch of keys in pianos and like musical instruments



Nov. 10, 1959 w. GNTHER MEANS FOR ADJUSTING THE TOUCH oF KEYS 1N PIANOS AND LIKE MUSICAL INSTRUMENTS Filed Oct. l5, 1957 United States Patent() MEANS FOR ADJUSTING THE TOUCH OF KEYS IN PIAN S AND LIKE MUSICAL INSTRUMENTS Walter Gnther, Hamburg, Germany, assignor to Steinway & Sons, Long Island City, N.Y., a corporation of New York Application October '15, 1957, Serial No. 690,256

Claims priority, application Germany October 17, 1956 1 Claim. (Cl. 84-439) The present invention relates to pianos and similar keyoperated musical instruments, and more particularly to improved means for controlling the touch of piano keys.

An object of the invention is to provide a greatly simplied system for adjusting the touch of piano keys which may be operated by persons of average skill.

Another object of the invention is to provide improved means for uniformly balancing the keys in pianos and like instruments irrespective of the density of materials of which the keys are made.

A further object of the invention is to provide a mechanism of the above character which allows for adjustments of touch without removal of piano parts.

A still further object of the invention is to provide a touch adjusting weight for piano keys which is positively arrested when the instrument is in use but may be conveniently `reached and adjusted by means of a simple tool and without removal of piano parts.

A yet further object of the invention is to provide adjustable means adapted to compensate for the changes in resistance to the depression of a key caused by friction between the moving parts of an upright or grand piano, and to regulate piano actions according to players taste.

It is known to provide one or more weights in the Ifront section of each piano key, usually short cylinders of lead, which act as counterweights against certain parts of the piano action resting on and/or bearing against that section of each key which is at the other side of the pivot. Each key must be carefully balanced so that the piano player, when striking a key, meets a predetermined resistance, generally a force between 45 and 50 grams. The number of weights necessary yfor properly adjusting the touch of a piano-key will vary depending on the weight of each individual weight, on the density of material of which the key is made, on the type of action (i.e. the overall weight of parts which act against the opposing end of the key), and on playing habits of the user. Before being shipped from the manufacturing plant, each piano is carefully adjusted and the number and position of touch adjusting weights in each key determined and checked by a skilled technician. Such minute work and individual insertion of one or more weights are time consuming and considerably increase the overall cost of the instrument.

The above enumerated drawbacks are overcome by the provision of a very simple and reliable mechanism associated with each piano key which consists of a longitudinally adjustable weight and means for moving the weight in either direction between the pivot and the playing end of a key. In accordance with one embodiment of my invention, a weight is installed in a longitudinal groove provided. in the piano key intermediate its playing end and the point about which the key pivots, and a conveniently accessible actuating member projects, for example, above the upper face of the key and is connected with the weight in such manner that the rotating ice actuating member causes the weight to move between the longitudinal ends of the key groove. The weight remains in a selected position when the actuating member is not rotated despite repeated striking of the key when the instrument is in use.

Other features, advantages and attributes of the novel touch adjusting mechanism will become apparent in the course of the following detailed description of two at this time preferred embodiments which are illustrated in the accompanying drawing, and the invention will be finally pointed out in the appended claims.

In the drawing,

Fig. 1 is a side elevational view of a grand piano key in partial section, showing the touch adjusting mechanism built therein adjacent to its playing end;

Fig. 2 is a greatly enlarged transverse section taken lon line 2 2 of Fig. l; and l Fig. 3 is a section similar to that of Fig. 2, but showing a slightly different weight and housing therefor.

Referring first to Fig. l, there is shown a Steinway (trademark) type grand action. The keyframe 10 supports a key 11; the action frame 12 carries the action mechanism which comprises the wippen 13 with balancer or repetition lever 14, and hammer 15 with its shank 16. Key 11 carries the back check 17 and a capstan screw 18, the latter abutting against the wippen 13. When the key is depressed at its (in the drawing) right-hand end 11a, it pivots about the Ibalance rail bearing 19 and lifts the back check 17 and capstan screw 18 thereby causing the wippen 13 to move the hammer 15 toward and into contact with the string 20. The left-hand end 11b of the key moves the underlever 21 and damper 22. in upward direction away from the string. The above described parts and the manner in which they operate are known and do not form part of my invention; they have been shown and their action described to indicate what resistance a players finger must overcome when the key 11 is depressed. As before stated, the required nger pressure may vary within a certain range and depends largely on the type of instrument, on the density of the material of Iwhich various parts are made, and on the users playing habits. The touch weight of a piano action is also determined to a great extent by the friction in action centers or hinge pins on which the parts move. This friction increases in damp weather when the cloth bushings swell up and make the action tighter. Tocarry out adjustments in the touch of each individual piano key, bores are customarily drilled into the key intermediate its playing end 11a and the bearing 19 for reception of lead weights at a proper distance from the bearing. Such adjustment is based on trial and error and requires great skill and considerable time. Two lead weights 33 are shown in the underlever 21. Their purpose is to insure rapid descent of damper 22, when the key is released and also to `eliminate undesirable sympathetic vibrations of the string.

In accordance with my invention, an elongated groove 24 is provided in a portion of the key 11 between its playing end 11a and the bearing 19. A housing 25 of preferably angular, for example, rectangular contour is inserted in the groove 24. A weight 26 in the form of an elongated metallic bar is slidably received in the housing 25 and is traversed by a threaded spindle 27 extending between the longitudinal ends of the housing. The spindle is rotatably supported in -two bearings 23a, 28h in the transverse vertical walls of the housing 25. The weight 26 has a threaded bore for the passage of spindle 27 and will thus travel between the longitudinal ends of the housing when the spindle is rotated in either direction. l In the embodiment shown in Figs. l and 2, the spindle 27 may be turned by means of a shaft 29 rotatably received in bearing fr@ on the housing 25 and projecting above the upper face of the key 11. The `lower end of shaft 29 carries a bevel gear 3l which meshes with a similar gear 32 at the lett-hand end of spindle 27. Shaft 2,9 may be rotated Ain either direction by the working end of a screwdriver', by'

a knife or similar suitable tool inserted into the slotted head 29a thereof. 1n this manner, the touch of key '11 is adjustable without adding or removing weights but merely by displacing the permanently installed weight toward or away from the point about which the key pivots, i.e. toward and away from the bearing 19. The touch may thus be adjusted within the customary range by a man of average skill for any desired iinger pressure. The weight 26 is held in the housing snugly enough so that it will not move when the shaft 29 is not rotated and should not be displaced when the piano is in actual use. The mass of the adjustable weight 26 is so selected as to cornpensate for the differences in density of materials of which the keys are made. ln this manner, the overall weight ot piano keys made of different types of wood may remain uniform by proper selection of the weight of member 26. As before stated, friction in the action centers increases in damp weather when the cloth bushings swell up and make the action tighter. Adjustment of the weight 26 toward or away from the bearing 19 is suficient to compensate for such changes in friction. By proper selection of gears 31, 32, precise adjustments of the weight can be made. Moreover, the friction between intermeshing elements 31, 32, 27 and 26 in that order, as well as the friction between members 27, 29 and their respective bearings 28e, 28h and 3d are suflicient to prevent any displacement of the weight when the piano is in play.

in its preferred form, the weight 26 is of rectangular cross-sectional contour and is snugly received in the hous ing 25. ln Figs. 1 and 2, the member 26 is nearly square. 1t cannot rotate with the spindle but immediately moves to right or to left when the shaft Z9 is rotated. It is advisable to locate shaft 29 between the inner end of the playing portion of the sharp B9 and the bearing 19, i.e.

v 4 Y in a location where it can be reached and conveniently rotated without removing the key from its base 11i. The expression playing portion is intended to denote that part of each sharp which normally extends above the upper surfaces of adjacent keys.

In the modification shown in Fig. 3, the housing 34 is cylindrical and defines a keyway 35' to receive the key 37 which'is integral with the weight 36 of circular crosssectional contour. Actuating shaft 318 has a hexagonal head 38a.

The invention is, of course, not limited to grand piano keys or to the specific form of mechanism shown in Figs. 1 to 3, but may be embodied in other types of key operated musical instruments.

What I claim and desire to protect by Letters Patent is:

in a piano like musical instrument, in combination: a plurality of keys and Sharps, each key having an upper face, a playing end and being rockable about a pivot point spaced from its playing end, and each sharp having a playing portion with an inner end spaced from the pivot point of the adjacent key, a weight longitudinally adjustably supported by each key between the playing end and the pivot point thereof, and means for moving said weights longitudinally `of the keys, said means comprising actuating members each extending above the upper face of each key intermediate the pivot point thereof and the inner end of the playing portion of the adjacent sharp, the weights being movable by said means between two spaced positions adjacent to the playing end and to the pivot point, respectively, of each key.

References Cited in the file of this patent .UNITED STATES PATENTS 478,552 Bassett July 12, 1892 882,814 Clemans aan Mar. 24, 1908 1,224,994 Anelli' May 8, 1917 1,341,035 Bell et al. May 25, 1920 1,589,745 Federle June 22, 1926 2,467,495 Pond Apr. 19, 1949 

